The folio tab widget carries a style sheet, and QStyleSheetStyle pins
the palette of every widget under it to the application palette in
force when the sheet was applied. After a live light/dark switch the
view's own palette() is therefore stale: the folio kept its dark sheet
after a switch to light, and kept its white sheet after a switch to
dark. PaletteGraphicsView now reads the application palette both for
the decision to invert and for the sheet and ink colors.
Test in tst_qetpalette: paletteViewFollowsTheApplicationUnderAStyleSheet
puts the view in a tab widget with a style sheet and switches the
application palette to dark and back.
The inverted painting, the rubber band replay and the changed()
receiver lived in DiagramView, which the unit tests cannot link, so the
update-flag regression was only covered through a stand-in view. They
now live in PaletteGraphicsView, a QGraphicsView subclass with no
other dependency, and DiagramView derives from it. The view tells a
subclass through paintingInverted(bool) when it renders for an
inverted display; DiagramView forwards that to the diagram. The grid
dot rule moves out of Diagram::drawBackground into
QET::Palette::gridDotColor().
tst_qetpalette now links the real class: gridDotColorSoftensInvertedDots,
paletteViewFollowsThePalette (light sheet, dark sheet at text contrast
with a red box still red and the paintingInverted calls in order, back
to light), paletteViewKeepsSceneUpdatesFlowing (three whole-scene
updates and a selection each repaint, scene set after construction),
paletteViewDrawsTheRubberBand.
Jeff Patterson